Patent GB-311373-A (GB)
Title: Improvements in key operated combination lock
IPC: E05B27/08
Filed: 1929-04-22
Abstract: 311,373. Mehren Lock Co., Inc., (Assignees of Mehren, O. D. von). May 10, 1928, [Convention date]. Keys ; locks permutation ; locks, revolving barrel. - A key-operated lock having permutation mechanism whereby the lock can only be operated by a key giving predetermined movements to a number of elements is so arranged that the permutation elements can be automatically re-set to suit a different key by unlocking with the old key and relocking with the new. Keys which can be altered to a new setting are also described. The lock shown is of revolving barrel type operating the bolt &c. (not shown) by means of a bar 9 in usual way. The rotatable barrel has an enlarged central cylindrical portion 5 and end portions 6, 7 of less diameter, and is rotatably housed in a casing 1. The portion 7 has a recess 10 to receive the key inserted through a keyhole in the front of the casing. Slidable elements 29 are movable axially in channels 17 - - 22 provided in the casing and in channels 11 - - 16 in the periphery of the barrel enlargement 5, normally registering with the channels in the casing. Six sliders with corresponding channels, arranged in diametrically-opposed groups of three, are shown, but any number may be used. The sliders are cut away so that, when in the central position shown in Fig. 6, they straddle the enlarged portion 5 of the barrel and the barrel is free to revolve. If one or more of the sliders be displaced in either direction from this position, an unmutilated end of the slider engages the channel in the part 5 and locks the barrel against rotation. The sliders are brought to the unlocking position by insertion of the proper key 102, Figs. 5, 9, which pushes plungers 34, each plunger having a terminal tinser 32 extending laterally through a slot in the barrel into the cut-away portion of the corresponding slider. The remainder of the cutaway portion is filled with spacing discs 36 disposed on opposite sides of the finger, and the extent of sliding movement necessary to bring a slider to unlocking position is determined by the relative numbers of discs on opposite sides of the finger 32, as shown in Fig. 9, thus fixing the relative position of a slider and its finger until the disposition of the spacing discs is altered. Sliders, discs, fingers and plungers 34 are normally urged to the left by corresponding springs 35. Normally, the key can only be inserted and removed from the keyhole in one position, but to enable the key to be removed for combination-changing purposes in a neutral position at right-angles to that in which it is inserted, a screw 46 is provided having a notch 47 which can be brought adjacent to the keyhole. The casing 1 has channels 23 - - 28, Fig. 7, disposed in groups in a position at right angles to the disposition of channels 17 - - 22, and each of these channels houses a cut-away slider 30. Sliders 30 are longer than sliders 29, have no locking function, and serve merely as disc-storing receptacles. With the sliders 29 as shown in Fig. 9, the discs 36 and ends of fingers- 32 are accommodated in the channels in barrelenlargement 5, and when the barrel is rotated through a right-angle, the discs are carried round thereby into the sliders 30, Fig. 5. If the key be now withdrawn, sliders 30 are moved to the left, Fig. 4, by the springs. When a key corresponding the required new setting of the mechanism is inserted, sliders 30 are moved inwards distances corresponding to the new setting, and when the barrel is returned through a right. angle, the spacing-discs corresponding with the new setting are carried thereby into the sliders 29. The screw 46 is then returned to the position shown in Fig. 1, and the lock can then be operated only by the new key until the setting is again charged. Figs. 23, 25. show a key which can be altered to a new setting. The key haschannels to receive the plungers 34 of the lock, the lengths of the channels being independently adjustable by plungers 103 which are held in the adjusted position by one of a number of grooves in the inner faces of slidable cover-plates 107 engaging lateral projections 105 at the inner ends of the plungers. Graduations 109 corresponding with the thickness of the spacing-discs 36 are provided on the key to facilitate setting and to allow, a note of the setting to be taken in case it should be necessary to replace a lost key. The cover plates are secured by screws 110, and a notch 111 engaged by the keyhole prevents removal of the key except in the predetermined positions described above. The Specification as open to inspection under Sect. 91 (3) (a) described a modified key, Fig. 26 (Cancelled), in which the plungers are held in adjusted position by a leaf spring detent 108<a> engaging serrations 105<a> in the edges of the plungers. A pivoted cover-plate 107<a> which can be secured by a screw 110<a> secures the plungers by preventing releasing movement of the d'etent, and also hides the adjustment devices and graduations. The cover may be further secured by a key ring passed through holes 117, 118. A form of key was also described having non-adjustable channels. This subject-matter does not appear in the Specification as accepted.